Researchers from the Universities of Sheffield and Copenhagen said they were “really excited” about the findings, published in the journal Nature, which could potentially save thousands of lives.

Breast cancer is the most common cancer among women in the UK, with around 50,000 cases a year, and 12,000 deaths.

Almost nine in ten deaths occur because disease has spread to the bone.

The new trials, in mice, identified an enzyme which is triggered by tumours in the breast, causing holes in the bones, which make them susceptible to the spread of disease.

The study found that treatment with bisphosphonate - an existing drug used to prevent and treat osteoporosis, was able to prevent changes to the bone, and block spread of disease.

The drugs, which prevent the loss of bone mass, are already prescribed to those at risk of osteoporotic fractures at a cost of around £1 a day.

Researchers said they now wanted to carry out research to establish exactly how the bone cells and enzymes interact, to develop the most effective treatments to block the spread of disease.

Dr Janine Erler, Associate Professor at the Biotech Research & Innovation Centre at the University of Copenhagen, study co-leader said the findings could transform treatment for breast cancer.

“Once cancer spreads to the bone it is very difficult to treat,” she said. “Our research has shed light on the way breast cancer cells prime the bone so it is ready for their arrival. If we were able to block this process and translate our work to the clinic, we could stop breast cancer in its tracks thereby extending patients’ lives.”

Co-author Dr Alison Gartland, from the University of Sheffield’s Department of Human Metabolism said the findings could extend thousands of lives.

“We are really excited about our results,” she said.

“This is important progress in the fight against breast cancer metastasis and these findings could lead to new treatments to stop secondary breast tumours growing in the bone, increasing the chances of survival for thousands of patients.”

The research, conducted at The Institute of Cancer Research, London, found that the enzyme LysYl Oxidase (LOX) released from the primary tumour causes holes in bone and prepares the bone for the future arrival of cancer cells.

Identifying LOX in oestrogen receptor negative (ER negative) breast cancer patients early, could allow doctors to block the enzyme’s activity, preventing bone damage and the spread of tumour cells to the bone (metastasis), halting the progression of the disease.

The researchers showed that treatment with bisphosphonate, an existing class of drug which prevents the loss of bone mass and is already used to treat diseases such as osteoporosis, was able to prevent the changes in the bone and the spread of the disease in mice.

Katherine Woods, Senior Research Communications Manager at Breast Cancer Campaign and Breakthrough Breast Cancer, said the findings opened up a whole new avenue for research for new treatments to block the spread of breast cancer.

She said: “The research also adds weight to the growing body of evidence supporting the role of bisphosphonates in stopping secondary breast cancer in its tracks.”

The charity said women living with secondary breast cancer were currently left to suffer bone pain and fractures, requiring surgery during the precious time they had left with loved ones.

Ms Woods said: “Secondary breast cancer kills 1,000 women each and every month in the UK alone and yet we still don’t know enough about how and why breast cancer spreads to stop it.”